Modify backpressure test to something sensible

test/build_lib_i2s_tests.sh

@@ -9,18 +9,6 @@ source ${FRAMEWORK_IO_ROOT}/tools/ci/helper_functions.sh
 
 # row format is: "make_target BOARD toolchain"
 declare -a applications=(
-    "test_hil_backpressure_test_32_768000_4_5_5"
-    "test_hil_backpressure_test_32_768000_4_0_10"
-    "test_hil_backpressure_test_32_768000_4_10_0"
-    "test_hil_backpressure_test_32_768000_3_5_5"
-    "test_hil_backpressure_test_32_768000_3_0_10"
-    "test_hil_backpressure_test_32_768000_3_10_0"
-    "test_hil_backpressure_test_32_768000_2_5_5"
-    "test_hil_backpressure_test_32_768000_2_0_10"
-    "test_hil_backpressure_test_32_768000_2_10_0"
-    "test_hil_backpressure_test_32_768000_1_5_5"
-    "test_hil_backpressure_test_32_768000_1_0_10"
-    "test_hil_backpressure_test_32_768000_1_10_0"
     "test_hil_backpressure_test_32_384000_4_5_5"
     "test_hil_backpressure_test_32_384000_4_0_10"
     "test_hil_backpressure_test_32_384000_4_10_0"
@@ -81,18 +69,6 @@ declare -a applications=(
     "test_hil_i2s_slave_test_32_1_4_0_inv"
     "test_hil_i2s_slave_test_32_1_0_4_inv"
     "test_hil_i2s_slave_test_32_1_2_2_inv"
-    "test_hil_backpressure_test_16_768000_4_5_5"
-    "test_hil_backpressure_test_16_768000_4_0_10"
-    "test_hil_backpressure_test_16_768000_4_10_0"
-    "test_hil_backpressure_test_16_768000_3_5_5"
-    "test_hil_backpressure_test_16_768000_3_0_10"
-    "test_hil_backpressure_test_16_768000_3_10_0"
-    "test_hil_backpressure_test_16_768000_2_5_5"
-    "test_hil_backpressure_test_16_768000_2_0_10"
-    "test_hil_backpressure_test_16_768000_2_10_0"
-    "test_hil_backpressure_test_16_768000_1_5_5"
-    "test_hil_backpressure_test_16_768000_1_0_10"
-    "test_hil_backpressure_test_16_768000_1_10_0"
     "test_hil_backpressure_test_16_384000_4_5_5"
     "test_hil_backpressure_test_16_384000_4_0_10"
     "test_hil_backpressure_test_16_384000_4_10_0"

test/lib_i2s/backpressure_test/backpressure_test.cmake

@@ -24,7 +24,7 @@ set(APP_LINK_OPTIONS
 # Tile Targets
 #**********************
 if(NOT DEFINED ENV{SAMPLE_RATES})
-    set(SAMPLE_RATES 768000 384000 192000)
+    set(SAMPLE_RATES 384000 192000)
 else()
     set(SAMPLE_RATES $ENV{SAMPLE_RATES})
 endif()

test/lib_i2s/backpressure_test/src/main.c

@@ -14,7 +14,7 @@
 #define BURN_THREADS    6
 #endif
 #ifndef SAMPLE_FREQUENCY
-#define SAMPLE_FREQUENCY 768000
+#define SAMPLE_FREQUENCY 192000
 #endif
 #ifndef TEST_LEN
 #define TEST_LEN 1000
@@ -44,6 +44,115 @@
 
 #define SETSR(c) asm volatile("setsr %0" : : "n"(c));
 
+enum {
+    SAMPLE_RATE_192000,
+    SAMPLE_RATE_384000,
+    NUM_SAMPLE_RATES
+}e_sample_rates;
+
+enum {
+    BITDEPTH_16,
+    BITDEPTH_32,
+    NUM_BIT_DEPTHS
+}e_bit_depth;
+
+enum {
+    NUM_I2S_LINES_1,
+    NUM_I2S_LINES_2,
+    NUM_I2S_LINES_3,
+    NUM_I2S_LINES_4,
+}e_channel_config;
+
+static int acceptable_receive_delay = 0, acceptable_send_delay = 0;
+static int acceptable_delay_ticks[NUM_SAMPLE_RATES][NUM_I2S_LINES_4+1][NUM_BIT_DEPTHS];
+
+static inline void populate_acceptable_delay_ticks()
+{
+    // These numbers are logged by running the test and logging the delay at the point at which the
+    // backpressure test starts failing.
+
+    // 192 KHz
+    acceptable_delay_ticks[SAMPLE_RATE_192000][NUM_I2S_LINES_1][BITDEPTH_16] = 185;
+    acceptable_delay_ticks[SAMPLE_RATE_192000][NUM_I2S_LINES_1][BITDEPTH_32] = 200;
+    acceptable_delay_ticks[SAMPLE_RATE_192000][NUM_I2S_LINES_2][BITDEPTH_16] = 155;
+    acceptable_delay_ticks[SAMPLE_RATE_192000][NUM_I2S_LINES_2][BITDEPTH_32] = 170;
+    acceptable_delay_ticks[SAMPLE_RATE_192000][NUM_I2S_LINES_3][BITDEPTH_16] = 130;
+    acceptable_delay_ticks[SAMPLE_RATE_192000][NUM_I2S_LINES_3][BITDEPTH_32] = 150;
+    acceptable_delay_ticks[SAMPLE_RATE_192000][NUM_I2S_LINES_4][BITDEPTH_16] = 100;
+    acceptable_delay_ticks[SAMPLE_RATE_192000][NUM_I2S_LINES_4][BITDEPTH_32] = 125;
+
+    // 384 KHz
+    acceptable_delay_ticks[SAMPLE_RATE_384000][NUM_I2S_LINES_1][BITDEPTH_16] = 60;
+    acceptable_delay_ticks[SAMPLE_RATE_384000][NUM_I2S_LINES_1][BITDEPTH_32] = 70;
+    acceptable_delay_ticks[SAMPLE_RATE_384000][NUM_I2S_LINES_2][BITDEPTH_16] = 35;
+    acceptable_delay_ticks[SAMPLE_RATE_384000][NUM_I2S_LINES_2][BITDEPTH_32] = 45;
+    acceptable_delay_ticks[SAMPLE_RATE_384000][NUM_I2S_LINES_3][BITDEPTH_16] = 5;
+    acceptable_delay_ticks[SAMPLE_RATE_384000][NUM_I2S_LINES_3][BITDEPTH_32] = 20;
+    acceptable_delay_ticks[SAMPLE_RATE_384000][NUM_I2S_LINES_4][BITDEPTH_16] = 0;
+    acceptable_delay_ticks[SAMPLE_RATE_384000][NUM_I2S_LINES_4][BITDEPTH_32] = 0;
+}
+
+void get_acceptable_delay()
+{
+    int sample_rate;
+    if(SAMPLE_FREQUENCY == 192000)
+    {
+        sample_rate = SAMPLE_RATE_192000;
+    }
+    else if(SAMPLE_FREQUENCY == 384000)
+    {
+        sample_rate = SAMPLE_RATE_384000;
+    }
+    else
+    {
+        printf("ERROR: Invalid sample rate %d\n", SAMPLE_FREQUENCY);
+        _Exit(1);
+    }
+
+    int bit_depth;
+    if(DATA_BITS == 16)
+    {
+        bit_depth = BITDEPTH_16;
+    }
+    else if(DATA_BITS == 32)
+    {
+        bit_depth = BITDEPTH_32;
+    }
+    else
+    {
+        printf("ERROR: Invalid bit_depth %d\n", DATA_BITS);
+        _Exit(1);
+    }
+    if((NUM_I2S_LINES < 1) || (NUM_I2S_LINES > 4))
+    {
+        printf("ERROR: Invalid NUM_I2S_LINES %d\n", NUM_I2S_LINES);
+        _Exit(1);
+    }
+    int delay = acceptable_delay_ticks[sample_rate][NUM_I2S_LINES-1][bit_depth];
+
+    // get the send and receive delay based on the
+    if((RECEIVE_DELAY_INCREMENT == 5) && (SEND_DELAY_INCREMENT == 5))
+    {
+        acceptable_receive_delay = delay;
+        acceptable_send_delay = delay;
+    }
+    else if((RECEIVE_DELAY_INCREMENT == 0) && (SEND_DELAY_INCREMENT == 10))
+    {
+        acceptable_receive_delay = 0;
+        acceptable_send_delay = 2*delay;
+    }
+    else if((RECEIVE_DELAY_INCREMENT == 10) && (SEND_DELAY_INCREMENT == 0))
+    {
+        acceptable_receive_delay = 2*delay;
+        acceptable_send_delay = 0;
+    }
+    else
+    {
+        printf("ERROR: Unsupported receive (%d) and send (%d) delay increment combination\n", RECEIVE_DELAY_INCREMENT, SEND_DELAY_INCREMENT);
+        _Exit(1);
+    }
+}
+
 /* Ports and clocks used by the application */
 port_t p_lrclk = XS1_PORT_1G;
 port_t p_bclk = XS1_PORT_1H;
@@ -54,7 +163,7 @@ port_t p_din [4] = {XS1_PORT_1I, XS1_PORT_1J, XS1_PORT_1K, XS1_PORT_1L};
 xclock_t mclk = XS1_CLKBLK_1;
 xclock_t bclk = XS1_CLKBLK_2;
 
-static volatile int receive_delay = 5000;
+static volatile int receive_delay = 0;
 static volatile int send_delay = 0;
 
 void i2s_init(void *app_data, i2s_config_t *i2s_config)
@@ -85,11 +194,6 @@ i2s_restart_t i2s_restart_check(void *app_data)
     return I2S_NO_RESTART;
 }
 
-#if DATA_BITS == 32
-#define OVERHEAD_TICKS 185 // Some of the period needs to be allowed for the callbacks
-#else
-#define OVERHEAD_TICKS 185 // Non-32b data widths take longer to process
-#endif
 #define JITTER  1   //Allow for rounding so does not break when diff = period + 1
 #define N_CYCLES_AT_DELAY   1 //How many LR clock cycles to measure at each backpressure delay value
 #define DIFF_WRAP_16(new, old)  (new > old ? new - old : new + 0x10000 - old)
@@ -121,28 +225,40 @@ void test_lr_period() {
         port_set_trigger_in_equal(p_lr_test, 0);
         (void) port_in(p_lr_test);
         counter++;
-        if (counter == N_CYCLES_AT_DELAY) {
-            receive_delay += RECEIVE_DELAY_INCREMENT;
-            send_delay += SEND_DELAY_INCREMENT;
-            if ((receive_delay + send_delay) > (period - OVERHEAD_TICKS)) {
-                printf("PASS\n");
-                _Exit(0);
-            }
-            counter = 0;
-        }
+
         port_set_trigger_in_equal(p_lr_test, 1);
         (void) port_in(p_lr_test);
         time = port_get_trigger_time(p_lr_test);
 
         int diff = DIFF_WRAP_16(time, time_old);
         if (diff > (period + JITTER)) {
-            printf("Backpressure breaks at receive delay ticks=%d, send delay ticks=%d\n",
-            receive_delay, send_delay);
-            printf("actual diff: %d, maximum (period + Jitter): %d\n",
-            diff, (period + JITTER));
-            _Exit(1);
+            // The delay we're able to add in the i2s_receive() function should be acceptable_receive_delay ticks or more
+            if(receive_delay < acceptable_receive_delay)
+            {
+                printf("Backpressure breaks at receive delay ticks = %d, acceptable receive delay = %d\n",
+                    receive_delay, acceptable_receive_delay);
+                printf("actual diff: %d, maximum (period + Jitter): %d\n", diff, (period + JITTER));
+                _Exit(1);
+            }
+
+            // The delay we're able to add in the i2s_send() function should be acceptable_send_delay ticks or more
+            if(send_delay < acceptable_send_delay)
+            {
+                printf("Backpressure breaks at send delay ticks = %d, acceptable send delay = %d\n",
+                    send_delay, acceptable_send_delay);
+                printf("actual diff: %d, maximum (period + Jitter): %d\n", diff, (period + JITTER));
+                _Exit(1);
+            }
+            printf("PASS\n");
+            _Exit(0);
         }
-    time_old = time;
+
+        if (counter == N_CYCLES_AT_DELAY) {
+            receive_delay += RECEIVE_DELAY_INCREMENT;
+            send_delay += SEND_DELAY_INCREMENT;
+            counter = 0;
+        }
+        time_old = time;
     }
 }
 
@@ -153,6 +269,9 @@ void burn(void) {
 }
 
 int main() {
+    populate_acceptable_delay_ticks();
+    get_acceptable_delay();
+
     i2s_callback_group_t i_i2s = {
             .init = (i2s_init_t) i2s_init,
             .restart_check = (i2s_restart_check_t) i2s_restart_check,

test/lib_i2s/test_backpressure.py

@@ -5,7 +5,7 @@
 import subprocess
 from pathlib import Path
 
-sample_rate_args = {"768kbps": 768000, "384kbps": 384000, "192kbps": 192000}
+sample_rate_args = {"384kbps": 384000, "192kbps": 192000}
 
 num_channels_args = {"1ch": 1, "2ch": 2, "3ch": 3, "4ch": 4}
 
@@ -41,9 +41,6 @@ def test_i2s_backpressure(
     send_increment,
     bitdepth,
 ):
-    if (num_channels != 4) and not nightly:
-        pytest.skip("Only run 4 channel tests unless it is a nightly")
-
     id_string = (
         f"{bitdepth}_{sample_rate}_{num_channels}_{receive_increment}_{send_increment}"
     )